This invention relates generally to signposts, and more specifically to signposts for use with signs mounted adjacent to roadways.
At least some known roadway signs include an anchor that is driven into the ground, an extended support that is coupled to the anchor such that the support extends above the ground, and a sign coupled to the support. Because of their proximity to the roadway, such road signs may be a hazard for errant vehicles.
The Federal Highways Administration (“FHWA”) has promulgated yielding criteria for signposts and structures that are located adjacent to designated traffic areas. The yielding criteria is intended to protect both the occupants of vehicles and to reduce property damage from collisions with these structures. For example, for small and intermediate roadside supports, the current FHWA standards require a structure that is weak enough to bend upon impact such that a vehicle may pass over the support structure with minimum deceleration. Thus, occupant interior impact may be avoided and vehicular damage can be minimized. After a collision, however, the entire roadway sign support needs to be replaced, including the anchor in many cases.
To avoid the cost of replacing the anchors after a collision, other known signposts have been designed such that the sign support shears from the anchor upon impact. As a result, with such designs, following a collision the anchor may subsequently be reused with a replacement support. Couplers machined or fabricated with pre-determined break points, such as shear bolts, have been used with some success to separate the sign support and the anchor, such that the anchor remains substantially undamaged when a vehicle collides with a signpost. However, such couplers may also be vulnerable to shearing from wind loads on a sign.
Other known sign supports are coupled to the anchor using threaded fasteners. More specifically, in such designs, the fasteners are tightened to a pre-determined torque to facilitate securely coupling the anchor and the sign support. However, properly torquing a plurality of threaded fasteners to couple the anchor to the sign support may be a difficult and time-consuming task. Moreover, because the pre-determined torque of the threaded fasteners is sometimes verified using a torque wrench, the number of tools and/or operations required to erect a roadway sign may be increased. As such, using a torque wrench to verify the torque of the threaded fasteners may increase the cost, the complexity, and/or the time it takes to erect a roadway sign.